“What times are these,” wrote Bertolt Brecht in his poem, ‘To Those Born After’, “when a talk about trees is almost a crime because it implies silence on so many wrongs?” Brecht’s grim point – that an appreciation of nature, beauty and art can feel criminally negligent in times of political crisis – is well taken. His famous lament was written in the late 1930s, as Hitler was coming to power, and there was little room for either trees or laughter. “The man who laughs,” Brecht wrote in the same poem, “Has simply not yet heard the terrible news.”

When William Kentridge, a South African artist of Jewish descent, began making art in a South Africa still under the thumb of apartheid, he faced a similar predicament. He was white, and from an affluent family. But he was also politically conscious: his father, one of South Africa’s leading defence lawyers, worked on prominent cases relating to the Sharpeville Massacre, the death of Steve Biko and the imprisonment of Mandela.

Kentridge was expected to become a lawyer himself, and presumably to fight for social justice through the law. But he chose another path – first the theatre, then art, and more recently an improvised, marvellously free-wheeling combination of both. Over time, he has become South Africa’s best-known living artist, celebrated internationally as one of the most fecund, original and intelligent artists of his time.

He deserves that reputation, as I expect most people who go to see William Kentridge: Five Themes at the Australian Centre for the Moving Image (ACMI) will come to agree.

Kentridge makes stop-motion animated films through a laborious process of drawing and erasing, arranging and rearranging. His early films, made between 1989 and 2003 – a period straddling the end of apartheid – were grouped under the title 9 Drawings for Projection. Set in Johannesburg and the surrounding landscape, they are political allegories with surrealistic inventions, and they revolve around three characters: an industrialist called Soho Eckstein, his disillusioned wife, and Felix Teitlebaum, a poetic dreamer who is most often shown naked. All three channel aspects of Kentridge himself, while reflecting back on the wider South African predicament.

He also builds sculptures out of improvised kitchen utensils, as well as making prints. And, in a return to the theatre work that first lured him away from the prospect of law, he has spent much of the past decade creating complicated sets, using animated projections, for operas by Mozart (The Magic Flute) and Shostakovich (The Nose).

His art is instantly recognisable, but it can seem weirdly style-less, in the way that an improvised campsite or caravan settlement can be. The accent, you feel, is always on ‘getting the job done’. It’s a practical approach that seems to make extra room for – rather than exclude or inhibit – Kentridge’s subtly poetic sensibility. The results are at once gauche and virtuosic; weighty and fleet of foot; ironic and heartfelt; poignantly quiet and rudely cacophonic. Above all, Kentridge’s work is humane, in the best sense of that word: it is steeped in the stuff of humanity.

The show – a retrospective divided into five parts – is overwhelmingly black-and-white, with a smudged appearance suggestive of hard labour under tawdry skies. It is dense with text and imagery and bristling with art-historical allusions.

Although Kentridge’s work is playful and often wryly self-mocking, it is impossible to look at without being acutely conscious of the effort that went into making it. A lot of the time, Kentridge is out to remind us how prosaic that effort is. You leave the show (which I saw last year at the Museum of Modern Art in New York) with an overwhelming sense of an artist who spends a huge portion of his life pacing back and forth between sheets of paper pinned to a studio wall and the tripod holding his camera. That’s what it takes to make stop-motion animations from drawings.

As if to reinforce the point, Kentridge – who often appears in his own animations, either re-created in charcoal lines or ‘in the flesh’ – is always seen wearing his trademark white shirt over a white singlet, with spectacles attached to a black string around his neck.

So what was it that led Kentridge into art? What possibilities did he see in it? And how did he justify art-making when, in his own country, people were being locked up, tortured, murdered, exploited and spiritually crushed as a direct result of government policy?

In a formulation that sounds almost like a pointed rebuke to the law, Kentridge has said he saw art as “a way of arriving at knowledge that is not subject to cross-examination”. Kentridge makes up his animated films as he goes along. His motto when making them, he claims, is ‘NO SCRIPT, NO STORYBOARD’. And his art flouts the first rule of cross-examination: that you know in advance the answer to every question you ask. Elsewhere he has spoken of the “seriousness of play”, claiming that “it’s always been in between the things I thought I was doing that the real work has happened”.

Throughout the years of apartheid and their aftermath, Kentridge was struggling to reconcile his own creative impulses with his position of privilege, his underlying sense of existential absurdity, and the brute fact of injustice all around him. None of it, of course, could be reconciled. But Kentridge faced the realities of his and his country’s predicament with tremendous honesty and empathy.

Almost ten years after the fall of apartheid, he was ready to turn inward. The results were a series of films, usually displayed as a multiscreen installation, called 7 Fragments for Georges Méliès, Journey to the Moon and Day for Night, which I consider his finest works. Combining video footage and animation with witty sleights of hand (playing footage in reverse, for instance, or speeding it up), they show the artist at work in his studio.

We see Kentridge catching sheets of paper that seem to accelerate through the air. We see him wandering through the studio. We see his hands at a table using ink, rags, coffee and torn-up paper to make and unmake magical imagery. We see him wiping away charcoal smudges on the page of a book to reveal a bright full moon, or using an espresso coffee cup as both telescope and microscope.

There are fleeting references to tropes in the earlier political films. But these are finally private, solipsistic and deeply moving films about creativity. More than anything, they convey an unforgettable picture of Kentridge’s own imagination – the restlessness, the boredom, the despair, the exuberance and wit, the free play of metaphor and association, and above all, the freedom to make things up as one goes along.

Kentridge described Journey to the Moon as “an attempt to escape” – presumably from the obligation to address politics. But even this most self-absorbed work continues to remind us of all the points of intersection between art and politics (most of them charged with paradoxes and bittersweet ironies).

Since art is an expression of freedom, and since freedom is always under threat, art can never, of course, not be political. Artists, moreover, live in society; they are social and political beings, subject to laws and witnesses to injustice just like the rest of us.

Simply by exercising their freedoms – the freedom to create, to dream, to refuse to follow orders – artists create a realm of experience that exists precisely as an antidote, and even a rebuke, to politics. It is a realm that keeps on prising open doors forever in the process of being shut.

Art can play a part in changing society, and activist political art has a noble lineage. But art’s grasp of the political realm (and Kentridge is exemplary in his sensitivity to this) is fragile. Its ability to effect change, or so history would suggest, is minimal.

Instead, art is most valuable (in the political sense) as a reminder of why change might be wanted; of the values, feelings and sensations – the possibilities – we might want, all of us, to fight for. And in that sense, a painting by Matisse might be more valuable as a motivating force than an agitprop poster by Barbara Kruger.

On the spectrum of political art, Kentridge exists somewhere between Matisse and Kruger. But with his nose for the kinds of truths that only art seems able to acknowledge, that only art seems able to bear (absurdity, futility, dejection, euphoria, love – the full gamut), he does much to unite the tightening constraints of politics with a deeper human dispensation. His work is worth getting to know.

William Kentridge: Five Themes will be held at ACMI from 8 March to 27 May 2012.

Sebastian Smee is the art critic for The Washington Post and winner of the 2011 Pulitzer Prize for criticism. His latest book is The Art of Rivalry: Four Friendships, Betrayals, and Breakthroughs in Modern Art.

“What times are these,” wrote Bertolt Brecht in his poem, ‘To Those Born After’, “when a talk about trees is almost a crime because it implies silence on so many wrongs?” Brecht’s grim point – that an appreciation of nature, beauty and art can feel criminally negligent in times of political crisis – is well taken. His famous lament was written in the late 1930s, as Hitler was coming to power, and there was little room for either trees or laughter. “The man who laughs,” Brecht wrote in the same poem, “Has simply not yet heard the terrible news.”

When William Kentridge, a South African artist of Jewish descent, began making art in a South Africa still under the thumb of apartheid, he faced a similar predicament. He was white, and from an affluent family. But he was also politically conscious: his father, one of South Africa’s leading defence lawyers, worked on prominent cases...